America’s crumbling infrastructure is causing an enormous and growing burden to our society. According to the American Society of Civil Engineers (ASCE), trillions of dollars are required to bring our highway, tunnel and waterworks infrastructure back to acceptable conditions.
Repairing and revitalizing our nation’s infrastructure in hard-to access areas demands self-powered solutions that deliver decades of maintenance-free performance in extreme environmental conditions. Intelligent decision-making from data sources such as non-destructive evaluations for stress and deterioration; enhanced service-life predictive modeling, and real-time traffic flow data.
Lithium battery chemistry is ideal for remote wireless infrastructure applications because lithium is the lightest non-gaseous metals, offering the highest specific energy (energy per unit weight) and energy density (energy per unit volume) of any chemistry. Lithium batteries are also non-aqueous, enabling certain cells to offer an extended temperature range of –55°C to 125°C.
Of all the lithium chemistries that are commercially available, only bobbin-type lithium thionyl chloride (LiSOCl2) chemistry can offer 40-year operating life due to its high potential and extremely low self-discharge of less than 1% per year. By contrast, inferior-made bobbin-type LiSOCl2 batteries can have a much shorter battery life expectancy.
Water utilities commonly deploy AMR/AMI meter reading devices to identify leaks, track customer usage and billing, and allow for remote shut-off and reactivation. These devices operate mainly in a standby mode.
When high pulses are required, an ideal solution is to specify battery was developed that combines a standard bobbin-type LiSOCl2 battery with a patented Hybrid Layer Capacitor (HLC). The battery and HLC work in parallel, with the battery supplying low-current power while the HLC supplies pulses up to 15 A, thus eliminating the voltage drop that normally occurs when a pulsed load is initially drawn without the balancing and current leakage problems associated with supercapacitors.
Tadian batteries can deliver moderate pulses without the use of an HLC, virtually eliminating initial voltage drop as well as voltage drop under pulse (or transient minimum voltage level). These batteries operate very efficiently, which can extend their operating life up to 15% in extremely hot or cold temperatures.
Resensys SenSpot structural integrity sensors measure stress, strain, tilt, inclination, vibration, displacement, deformation, temperature, and humidity in various applications, including bridges, tunnels, large commercial buildings, towers, and pipelines. This device draws only microamps of energy while sampling data once a minute, and uses a proprietary low power communications protocol to minimize energy consumption.
Resensys chose Tadiran TL-5902 ½ AA batteries that feature an annual self-discharge rate of less than 1% per year, providing a minimum guaranteed service life of 10 years, with the device rated to work much longer.
On behalf of PennDOT, electrical engineers from the University of Pittsburgh have developed a sensor that detects erosion within the concrete aggregate that surrounds bridge abutments, or “bridge scour.” Over time, waterflow erodes aggregate, especially during high water events. Their solution was to employ multiple wireless sensors housed in watertight ¾” PVC tubes that are strategically placed into vertically oriented holes bored into the aggregate. Each sensor is individually encoded to denote the criticality of the location, providing PennDOT with an early warning system in case of a potential structural failure.
In standby mode the battery remains disconnected. The battery activates when the sensor is dislodged and turns horizontally, enabling the device to transmit RFID signals to a nearby transceiver for approximately 30 minutes before the battery is exhausting. A TLM-1550HP battery enables the device to be inactive for extended periods then power up to deliver short-term, high drain requirements.